/* *****************************************************************************
 * The MIT License
 *
 * Copyright (c) 2010 LeafLabs LLC.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * ****************************************************************************/

/**
 *  @file hardware.c
 *
 *  @brief init routines to setup clocks, interrupts, also destructor functions.
 *  does not include USB stuff. EEPROM read/write functions.
 *
 */

#include "hardware.h"

void setPin(u32 bank, u8 pin) {
  u32 pinMask = 0x1 << (pin);
  SET_REG(GPIO_BSRR(bank),pinMask);
}

void resetPin(u32 bank, u8 pin) {
  u32 pinMask = 0x1 << (16+pin);
  SET_REG(GPIO_BSRR(bank),pinMask);
}

bool readPin(u32 bank, u8 pin) {
  // todo, implement read
  if(GET_REG(GPIO_IDR(bank)) & (0x01 << pin)) {
    return TRUE;
  } else {
    return FALSE;
  }
}

void strobePin(u32 bank, u8 pin, u8 count, u32 rate) {
  resetPin(bank,pin);

  u32 c;
  while (count-- >0) {
    for (c=rate;c>0;c--) {
      asm volatile ("nop");
    }
    setPin(bank,pin);
    for (c=rate;c>0;c--) {
      asm volatile ("nop");
    }
    resetPin(bank,pin);
  } 
} 

void systemReset(void) {
  SET_REG(RCC_CR, GET_REG(RCC_CR)     | 0x00000001);
  SET_REG(RCC_CFGR, GET_REG(RCC_CFGR) & 0xF8FF0000);
  SET_REG(RCC_CR, GET_REG(RCC_CR)     & 0xFEF6FFFF);
  SET_REG(RCC_CR, GET_REG(RCC_CR)     & 0xFFFBFFFF);
  SET_REG(RCC_CFGR, GET_REG(RCC_CFGR) & 0xFF80FFFF);

  SET_REG(RCC_CIR, 0x00000000);  /* disable all RCC interrupts */
}

void setupCLK (void) {
  /* enable HSE */
  SET_REG(RCC_CR,GET_REG(RCC_CR) | 0x00010001);
  while ((GET_REG(RCC_CR) & 0x00020000) == 0); /* for it to come on */
  
  /* enable flash prefetch buffer */
  SET_REG(FLASH_ACR, 0x00000012);

  /* Configure PLL */
  SET_REG(RCC_CFGR,GET_REG(RCC_CFGR) | 0x001D0400);  /* pll=72Mhz,APB1=36Mhz,AHB=72Mhz */
  SET_REG(RCC_CR,GET_REG(RCC_CR)     | 0x01000000);  /* enable the pll */
  while ((GET_REG(RCC_CR) & 0x03000000) == 0);         /* wait for it to come on */
  
  /* Set SYSCLK as PLL */
  SET_REG(RCC_CFGR,GET_REG(RCC_CFGR) | 0x00000002);
  while ((GET_REG(RCC_CFGR) & 0x00000008) == 0); /* wait for it to come on */
}

void setupLED (void) {
  // todo, swap out hardcoded pin/bank with macro
  u32 rwmVal; /* read-write-modify place holder var */

  /* Setup APB2 (GPIOB,GPIOA) */
  rwmVal =  GET_REG(RCC_APB2ENR);
  rwmVal |= 0x0000000C;
  SET_REG(RCC_APB2ENR,rwmVal);

  /* Setup GPIOB Pin 5 as PP Out */
 // SET_REG(GPIO_CRL(GPIOB), 0x00100000);

  rwmVal =  GET_REG(GPIO_CRL(GPIOB));
  rwmVal &= 0xFF0FFFFF;
  rwmVal |= 0x00100000;
  SET_REG(GPIO_CRL(GPIOB),rwmVal);

  setPin(GPIOB,5);
}

void setupBUTTON (void) {
  // todo, swap out hardcoded pin/bank with macro
  u32 rwmVal; /* read-write-modify place holder var */

  /* Setup APB2 (GPIOA) */
  rwmVal =  GET_REG(RCC_APB2ENR);
  rwmVal |= 0x00000004;
  SET_REG(RCC_APB2ENR,rwmVal);

  /* Setup GPIOA Pin 0 as PP Out */
  rwmVal =  GET_REG(GPIO_CRL(GPIOA));
  rwmVal &= 0xFFFFFFF0;
  rwmVal |= 0x00000008;
  SET_REG(GPIO_CRL(GPIOA),rwmVal);

 rwmVal =  GET_REG(GPIO_ODR(GPIOA));
   
  rwmVal |= 0x00000001;
  SET_REG(GPIO_ODR(GPIOA),rwmVal);

}

void setupFLASH() {
  /* configure the HSI oscillator */
  if ((pRCC->CR & 0x01) == 0x00) {
    u32 rwmVal = pRCC->CR;
    rwmVal |= 0x01;
    pRCC->CR = rwmVal;
  }

  /* wait for it to come on */
  while ((pRCC->CR & 0x02) == 0x00) {}
}

bool checkUserCode (u32 usrAddr) {
  u32 sp = *(vu32*) usrAddr;

  if ((sp & 0x2FFE0000) == 0x20000000) {
    return (TRUE);
  } else {
    return (FALSE);
  }
}

void jumpToUser (u32 usrAddr) {
  typedef void (*funcPtr)(void);

  u32 jumpAddr = *(vu32*) (usrAddr + 0x04); /* reset ptr in vector table */  
  funcPtr usrMain = (funcPtr) jumpAddr;

  /* tear down all the dfu related setup */
  // disable usb interrupts, clear them, turn off usb, set the disc pin
  // todo pick exactly what we want to do here, now its just a conservative 
  flashLock();
  usbDsbISR();
  nvicDisableInterrupts();
  resetPin(GPIOC,10); // disconnect usb from host. todo, macroize pin
  systemReset(); // resets clocks and periphs, not core regs
  

  __MSR_MSP(*(vu32*) usrAddr);              /* set the users stack ptr */

  usrMain();                                /* go! */
}

void nvicInit(NVIC_InitTypeDef* NVIC_InitStruct) {
  u32 tmppriority = 0x00;
  u32 tmpreg      = 0x00;
  u32 tmpmask     = 0x00;
  u32 tmppre      = 0;
  u32 tmpsub      = 0x0F;

  SCB_TypeDef* rSCB = (SCB_TypeDef *) SCB_BASE;
  NVIC_TypeDef* rNVIC = (NVIC_TypeDef *) NVIC_BASE;


  /* Compute the Corresponding IRQ Priority --------------------------------*/    
  tmppriority = (0x700 - (rSCB->AIRCR & (u32)0x700))>> 0x08;
  tmppre = (0x4 - tmppriority);
  tmpsub = tmpsub >> tmppriority;
  
  tmppriority = (u32)NVIC_InitStruct->NVIC_IRQChannelPreemptionPriority << tmppre;
  tmppriority |=  NVIC_InitStruct->NVIC_IRQChannelSubPriority & tmpsub;

  tmppriority = tmppriority << 0x04;
  tmppriority = ((u32)tmppriority) << ((NVIC_InitStruct->NVIC_IRQChannel & (u8)0x03) * 0x08);
    
  tmpreg = rNVIC->IPR[(NVIC_InitStruct->NVIC_IRQChannel >> 0x02)];
  tmpmask = (u32)0xFF << ((NVIC_InitStruct->NVIC_IRQChannel & (u8)0x03) * 0x08);
  tmpreg &= ~tmpmask;
  tmppriority &= tmpmask;  
  tmpreg |= tmppriority;

  rNVIC->IPR[(NVIC_InitStruct->NVIC_IRQChannel >> 0x02)] = tmpreg;
    
  /* Enable the Selected IRQ Channels --------------------------------------*/
  rNVIC->ISER[(NVIC_InitStruct->NVIC_IRQChannel >> 0x05)] =
    (u32)0x01 << (NVIC_InitStruct->NVIC_IRQChannel & (u8)0x1F);
}

void nvicDisableInterrupts() {
  NVIC_TypeDef* rNVIC = (NVIC_TypeDef *) NVIC_BASE;
  rNVIC->ICER[0] = 0xFFFFFFFF;
  rNVIC->ICER[1] = 0xFFFFFFFF;
  rNVIC->ICPR[0] = 0xFFFFFFFF;
  rNVIC->ICPR[1] = 0xFFFFFFFF;

  SET_REG(STK_CTRL,0x04); /* disable the systick, which operates separately from nvic */
}

void systemHardReset(void) {
  SCB_TypeDef* rSCB = (SCB_TypeDef *) SCB_BASE;
  
  /* Reset  */
  rSCB->AIRCR = (u32)AIRCR_RESET_REQ;

  /*  should never get here */
  while (1) {
    asm volatile("nop");
  }
}

bool flashErasePage(u32 pageAddr) {
  u32 rwmVal = GET_REG(FLASH_CR);
  rwmVal = FLASH_CR_PER;
  SET_REG(FLASH_CR,rwmVal);

  while (GET_REG(FLASH_SR) & FLASH_SR_BSY) {}
  SET_REG(FLASH_AR,pageAddr);
  SET_REG(FLASH_CR,FLASH_CR_START | FLASH_CR_PER);
  while (GET_REG(FLASH_SR) & FLASH_SR_BSY) {}

  /* todo: verify the page was erased */

  rwmVal = 0x00;
  SET_REG(FLASH_CR,rwmVal);

  return TRUE;
}
bool flashErasePages(u32 pageAddr, u16 n) {
  while (n-->0) {
    if (!flashErasePage(pageAddr+0x400*n)) {
      return FALSE;
    }
  }

  return TRUE;
}

bool flashWriteWord(u32 addr, u32 word) {
  vu16 *flashAddr = (vu16*)addr;
  vu32 lhWord = (vu32)word & 0x0000FFFF;
  vu32 hhWord = ((vu32)word & 0xFFFF0000)>>16;

  u32 rwmVal = GET_REG(FLASH_CR);
  SET_REG(FLASH_CR,FLASH_CR_PG);

  /* apparently we need not write to FLASH_AR and can
     simply do a native write of a half word */
  while (GET_REG(FLASH_SR) & FLASH_SR_BSY) {}
  *(flashAddr+0x01) = (vu16)hhWord;
  while (GET_REG(FLASH_SR) & FLASH_SR_BSY) {}
  *(flashAddr) = (vu16)lhWord;
  while (GET_REG(FLASH_SR) & FLASH_SR_BSY) {}

  rwmVal &= 0xFFFFFFFE;
  SET_REG(FLASH_CR,rwmVal);

  /* verify the write */
  if (*(vu32*)addr != word) {
    return FALSE;
  }

  return TRUE;
}

void flashLock() {
  /* take down the HSI oscillator? it may be in use elsewhere */

  /* ensure all FPEC functions disabled and lock the FPEC */
  SET_REG(FLASH_CR,0x00000080);
}

void flashUnlock() {
  /* unlock the flash */
  SET_REG(FLASH_KEYR,FLASH_KEY1);
  SET_REG(FLASH_KEYR,FLASH_KEY2);
}




